1. Field of the Invention
This invention is in the general field of dry cleaning of clothing, textiles, fabrics and the like. The invention is more particularly directed to a method and apparatus for dry cleaning fabrics using a solvent not heretofore used in dry cleaning machines. The invention is more particularly directed to a dry cleaning apparatus wherein a silicon-based solvent is utilized which has a desirable flash point rating (over 140 degrees Fahrenheit) and fabric-safe qualities (non-dye pulling and non-shrinkage) together with superior solvency for fatty acids, grease and oils in a specially designed dry cleaning process.
2. Prior Art
Dry cleaning is a major industry throughout the world. In the United States alone, there are more than forty thousand dry cleaners (many of these have multiple locations).
The dry cleaning industry is an essential industry in the present economy. Many articles of clothing (and other items) must be dry cleaned in order to remain clean (the removal of body fats and oils), and presentable (do not shrink or discolor clothing).
The most widely used dry cleaning solvent until now has been Perc. There are numerous disadvantages to Perc including its toxicity and odor. The machinery widely used, until now, has been manufactured specifically for use with Perc. This has been another limiting factor in the industry.
Another problem in this field is that different fabrics require different handling in the presently used systems in order to prevent damage to the fabrics during the dry cleaning process.
The prior art in dry cleaning includes the use of various solvents with appropriate machinery to accomplish the cleaning. In the most recent past, the solvent most widely used has been perchloroethylene (herein generally referred to as "Perc"). Perc has the advantage of being an excellent cleaning solvent, but the disadvantage of being a major health and environmental hazard (i.e., it has been linked to numerous forms of cancer and it is very destructive to ground water and aquatic life). In some areas Perc is no longer allowed to be used. Additionally, in the past other solvents such as petroleum-based solvents and glycol ethers and esters have been tried and used. These various solvents have been used with mixed cleaning results and problematic fabric/textile compatibility as compared to the results obtained with Perc.
The present invention is distinct from the prior art that it relies upon a non-Perc solvent with superior characteristics as described below, and used in a method involving dry cleaning machinery which has been specially designed for the solvent.
The only use of a cyclic siloxane composition for cleaning purposes is disclosed in U.S. Pat. No. 4,685,930 to Kasprzak. However, the disclosure therein is for spot cleaning applications only. There is no disclosure of immersing articles into the cyclic siloxane nor is there any suggestion of using the cyclic siloxane in a dry cleaning machine. Moreover, there is no suggestion of subjecting such articles immersed in cyclic siloxane to agitation, spinning, partial vacuum and heating in a continuous process to dry clean articles in a bulk process for removing fats, oils, grease and other soils from a large number of entire clothing articles.